Page:Philosophical Transactions - Volume 012.djvu/123

 Upon the Surface of the Earth, in many places, lie an abundance of rough Stones, some of them of a vast bulk; but where they sink their Mines, they rather meet with Veins of Scaly Stone, than hard and solid Rocks. Within the Forest they find great plenty of Coal and Iron-Ore; and in some places, Red and Yellow Oker: which are all the Minerals, that are yet discovered there.

I have been the more particular in this description, because I think it not impossible, that by an exact comparing of the Nature and Productions of such Soyls, where Minerals are usually formed, we may arrive to a certain knowledge, or at least a very probable conjecture, in what places we ought to search after their several sorts, and when to desist.

The Iron-Ore, which is the principal Manufacture here, and by which most of the Inhabitants subsist, is found in great abundance in most parts of the Forest: differing both in colour, weight, and goodness. The best, which they call their Brush-Ore, is of a Blewish colour; very ponderous, and full of little shining Specks like grains of Silver. This affords the greatest quantity of Iron; but being melted alone produceth a Metal very short and brittle, and therefore not so fit for common use.

To remedy this Inconveniency, they make use of another sort of Material, which they call their Cynder, and is nothing else, but the Refuse of the Ore after the Metal hath been extracted; which being mingled with the other in a due quantity, gives it that excellent temper of Toughness, for which this Iron is preferred before any that is brought from Forein parts.

But to understand this rightly, it is to be noted, That in former times, when their Works were few, and their Vent small, they made use of no other Bellows, but such as were moved by the Strength of men: by reason whereof their Fires were much less intense, than in the Furnaces they now employ. So that having in them melted down only the principal part of the Ore; they rejected the rest as useless, and not worth their charge. This they call their Cynder, which is now found in an unexhaustible quantity through all parts of the Countrey, where any former Works have stood.

After they have provided their Ore, their first work is to Calcine it; which is done in Kilns, much after the fashion of our ordinary Lime-Kilns. These they fill up to the top with